According to an article by the UK's Daily Mail, department store make-up samples are a playground for bacteria, mould and even fecal matter.
TV show Good Morning America made the revelations after it went undercover to test the health safety of shared eye-shadows, foundations and lipsticks found at beauty counters. Their team took samples, using sterile swabs, from 10 stores across two American states. The evidence was then analysed in New York University's microbiology department.
The tests showed that one out of every five samples were brimming with mould, yeast or fecal matter as a result of hundreds of people using them on a daily basis. Brushes, foundations, eyeshadow and eyeliner were found to be the main bacteria-laden culprits. Some testers were carrying strains of bacteria that according to Philip Tierno, Director of Microbiology at NYU Langone Medical Centre, can make you ill.
"If you have an open cut, you might not want to go the route of using make-up that has been used by other people," he said.
The investigations also found beauty counters only replace their make-up samples, on average, once a year.
How to protect yourself
* Make-up experts suggest consumers test foundations and concealers on the neck rather than the face.
* With lipstick, they recommend testing colours on the tip of your finger. However, this still poses a problem considering the amount of times hands come into contact with the mouth. A study in 2011 by the London School of Hygiene and Tropical Medicine and Queen Mary, University of London found that only 10-12% of people wash their hands after going to the toilet.
* For eyeshadow and eyeliner, experts recommend using a disposable applicator on the back of your hand.